Roll changing apparatus

ABSTRACT

Apparatus for removing work-roll and backup roll sets from fourhigh rolling mills. The disclosed apparatus includes a rotatable platform positioned adjacent a mill stand and arranged for selective horizontal rotation and/or elevation. Additionally, there is disclosed a mill stand provided with means for shifting rolls and roll sets vertically to facilitate changing.

United States Patent lnventor William George Sherwood Salem, Ohio Appl.No. 793,783 Filed Jan. 24, 1969 Patented June 8, 1971 Assignee Gulf 8:Western industrial Products Company Grand Rapids, Mich.

ROLL CHANGING APPARATUS 13 Claims, 22 Drawing Figs.

US. Cl 72/239, 72/245 Int. Cl B2lb 31/08, 8211) 31/32 Field of Search72/237, 238, 239, 241, 243, 245;108/94, 103,139,141; 104/35, 36, 37, 47

[56] References Cited UNITED STATES PATENTS 1,031,055 7/1912 Edwards...72/238 2,987,008 6/1961 Melmer..... 104/36 3,208,260 9/1965 Sieger etal. 72/239 3,394,576 7/1968 Shumaker 72/239 Primary Examiner-Charles W.Lanham Assistant Examiner-R. M. Rogers Attorney-Meyer, Tilberry and BodyPATENTEnJun amen 35 3195 sum USUF 12 INVENTOR. WILLIAM C. SHERWOOD "izyn, 74W #34;

A TTOF/VEVI PATENTED JUN 8 1971 SHEET 05 [1F INVENTOR. WILLIAM G.SHERWOOD PATENTEDJIJN 8:971 3,5831% sum UBUF 12 INVENTOR.

WILLIAM G. SHERWOOD PATENTEDJUN 8|97| sum D7UF 12 92 8 N 3 INVENTOR! 8 7WILLIAM G. SHERWOOD A TTOF/Vf Y5.

Pmmw JUN 8197:

SHEET 08 0F 12 OmN m T N E V m LLIAM G. SHE RWOOD 777 if A 7 TUBA/ZPATEN-TEDJUN 8B7! SHEET 3583195 INVENTOR. WILLIAM G. SHERWOOD imyPATENTEDJUN am 3583.195

' sum -100F 12 PATENTEDJUN 8|97l $583,195

sum MM 12 F. Z BYWILLIAM c. SHERWOOD PATENTEDJUN 8I97| 3583.195

SHEET 120F 12 INVENTOR. WILLIAM G. SH ERWOOD ROLL CHANGING APPARATUS Thepresent invention is directed toward the rolling mill art and, moreparticularly, to an improved apparatus for changing the rolls in a millstand.

The invention is especially suited for use in changing both the backuprolls and the work-rolls in a four-high mill stand and will be describedwith particular reference thereto; however, it will be appreciated thatthe invention is capable of broader application and could be used forchanging the rolls in a variety of types of mill stands for example, twoand threehigh stands.

Apparatus for changing the work-rolls in a four-high mill stand is knownwhich includes a horizontal, rotatably mounted platform. The platform ispositioned adjacent to the mill stand with its axis of rotation offsetfrom the plane containing the axes of rotation of the rolls.Additionally, the top surface of the platform is in generally the sameplane as the lower surface of the lower work-roll.

To use the described apparatus for changing work-roll sets (i.e. a "set"including both an upper and a lower work-roll), a new or reconditionedroll set is positioned on the platform at one side out of alignment withthe set in the mill stand. The used work-roll set is then moved from thestand onto the diagonally opposite side of the platform. Thereafter, theplatform is rotated 180 to bring the new set into alignment with thestand to allow it to be pushed or pulled directly into position in thestand.

The above-discussed apparatus is advantageous in that it permitswork-roll sets to be changed relatively quickly; however, it doespresent substantial problems when it is desired to change the backuprolls. Although backup rolls must be changed at relatively less frequentintervals than work-rolls, none-the-less, the loss in production timeand the labor cost involved in changing the backup rolls can beconsiderable. The noted apparatus does nothing to facilitate backup rollchanging and, in fact, can add to the time and problems involved. As canbe appreciated, with the top surface of the platform in generally thesame plane as the lower surface of the bottom work-roll, the body of theplatform effectively prevents movement of the bottom work-roll out ofthe mill stand. For this reason, the apparatus must be substantiallydismantled prior to backup roll removal. Additionally, with theapparatus removed it is still necessary to remove the backup rolls bythe use of a C-hook or sled, procedures which can be both difficult andsomewhat dangerous.

The present invention provides an improvement to the above-discussedapparatus which allows both work-rolls and backup rolls to be rapidlychanged without the necessity of dismantling any structure; further,this is accomplished with a minimum of additional structure and only anominal increase in first cost.

Specifically in accordance with the invention, the combination of a millstand including a plurality of generally horizontal rolls and arotatably mounted platform having a generally horizontal roll supportsurface is provided with the improvement which includes means forselectively producing relative vertical movement between the supportsurface and the rolls whereby the support surface can be brought intoposition for receiving all of the rolls in the stand.

In accordance with a more limited aspect of the invention, means areprovided to shift the support surface of the platform between at leasttwo predetermined elevations and power means are provided for rotatingthe platform about its axis of rotation in both of the two predeterminedelevations.

Accordingly, aprimary object of the invention is the provision of arotatable platform type roll changing apparatus which can be utilizedfor changing either the work-rolls or backup rolls ofa four-high millstand.

Another object is the provision ofa mill and rotary-type roll changingapparatus which are arranged to permit relative vertical movementbetween the rolls in the stand and the roll support surface of theapparatus so that all of the rolls can be changed.

A still further object is the provision of apparatus of the typedescribed wherein the roll inserting and removing apparatus can be usedfor charging both the backup rolls and the workrolls in a four-highmill.

Yet another object is the provision of a four-high mill stand withbackup rolls which can be inserted as a set and, after insertion, beautomatically separated to receive work-rolls therebetween as a set.

Still yet another object is the provision of a four-high mill stand andassociated roll changing apparatus which permit sequential removal ofwork-rolls and backup rolls without modifying or disassembling the millstand or roll changing apparatus.

Other objects are the provision of an apparatus of the type describedwhich is relatively simple and reliable in operation and which greatlyreduces mill down time during backup roll changing in a four-high mill.

These and other objects and advantages will become apparent from thefollowing description when read in conjunction with the accompanyingdrawings wherein:

FIG. I is a side elevation of a four-high rolling mill stand providedwith a roll changing apparatus formed in accordance with a preferredembodiment of the invention;

FIG. 2 is a plan view taken on line 2-2 of FIG. 1;

FIG. 3 is an enlarged side view of the mill stand shown in FIG. 1showing the rolls in their working position;

FIG. 4 is a view similar to FIG. 3, but showing the rolls in a positionwherein the work-rolls can be removed;

FIG. 5 is a view similar to FIGS. 3 and 4 but showing the mill standwhen the work-rolls have been removed and the backup rolls are inposition for removal;

FIG. 5a is a detailed sectional view taken on line 5a-5a of FIG. 5;

FIGS. 6 and 7 are plan views similar to FIG. 2 but showing the apparatusfunctioning to remove the work-rolls, and backup rolls, respectively;

FIG. 8 is a partial side elevational view similar to FIG. 1 but showingin somewhat more detail the connection arrangements for engaging therolls and removing them;

FIG. 9 is a view taken on line 9-9 of FIG. 6 and showing the connectionarrangement between the backup roll and the inserting and removalapparatus;

FIG. 10 is a view taken on line 10-10 of FIG. 7 showing in detail theconnection arrangement between the work-rolls and the inserting andremoval apparatus;

FIG. 11 is a cross-sectional view taken through the top of the millstand and showing an upper roll balance mechanism which has beenmodified for raising the rolls during the roll changing operation;

FIG. 12 is an end view of that portion of the apparatus shown in FIG.11;

FIG. 13 is a cross-sectional view through the bottom of the mill standand showing the apparatus used for supporting the roll assemblies in araised position during insertion and removal of the roll assemblies fromthe stand;

FIG. 14 is a cross-sectional view taken on line 14-14 of FIG. 13;

FIG. 15 is a cross-sectional view taken through the bottom of the millstand on a vertical plane parallel with the roll axes to show themechanism utilized to raise and lower the roll removing track sectionsused in the preferred embodiment of the present invention;

FIG. 16 is a view taken on line l616 ofFIG. 15;

FIG. 17 is an enlarged plan view of the roll removing and insertingplatform;

FIG. 18 is a cross-sectional view taken on line 18-18 of FIG. 17 andshowing the structural details of the roll removing platform;

FIG. 21 is an enlarged cross-sectional view taken on line 2I-2l of FIG.19.

Referring now more particularly to the drawings wherein the showings arefor the purpose of illustrating a preferred embodiment of the inventiononly and not the purpose of limiting same, FIGS. 1 and 2 show theoverall arrangement of a roll receiving and handling assembly Aassociated with a mill stand B. Positioned on the side of the mill stand8 opposite from the roll receiving and handling assembly A is aninserting and withdrawing apparatus C which functions to move the rollsand roll sets into and out of the mill stand.

The Roll Receiving And Handling Apparatus A As shown, the assembly Aincludes a rotatable platform 10 which is mounted adjacent the millstand B for rotation about a vertically extending axis identified withthe reference letter P. The axis of rotation of the platform 10 isoffset from the vertical plane which contains the axes of the rolls ofthe mill stand B. This plane is noted by reference numeral 12 in FIG. 1.

Broadly, this general arrangement is well known in the art and haspreviously been used for facilitating changing of workroll sets. In thepast however, the platform was positioned so that its top or rollreceiving surface 14 was generally at the same level as the lower edgeof the bottom work-roll of the work-roll set. In operation, a newwork-roll set would be positioned on the platform at a locationindicated by the dotted line showing 16 in FIG. 7. The used work-rollset would then be moved out of the mill stand into the dotted lineposition identified as 17 in FIG. 7. Thereafter the platform would berotated to bring the new work-roll set 16 into alignment with the millstand window. This new set could then be inserted into the mill standand the used set taken from the platform for reconditioning.

This prior arrangement was generally satisfactory for removingwork-rolls; however, as can be seen in FIG. I, with the top of theplatform aligned with the bottom of the lower work-roll set, the lowerbackup roll is effectively blocked and can not be removed withoutdisassembling at least a portion of the platform. Obviously, theplatform could not be used for backup roll removal thus necessitatingthe use of overhead cranes and other similar apparatus. Alternately, anextremely complex multilevel removing apparatus was required.

The subject invention overcomes the prior problems and provides a rollremoving and handling platform arrangement which can be used forremoving both the work-roll set and the backup rolls. Although, as willbecome apparent as the description proceeds, a roll-receiving andhandling platform A formed in accordance with the invention could have avariety of specific structural configurations, the preferredconstruction of the platform is as shown in FIGS. 17-20.

Referring particularly to the FIGS. 17 and 18, it is seen that theplatform 10 includes a main top support member in the form of agenerally circular plate 20. Plate 20 has a circumferentially positionedframe member 22 extending downwardly from its lower surface andterminating in a transversely extending circumferential flange 24. Aswill subsequently be described, flange 24 serves as a drive member forthe platform rotating drive unit.

The platform 20 is supported from an intermediate frame assembly 30which, as best shown in FIGS. 18 and 19, includes four beams 31 through34 connected to form a generally square frame. A similar beam member 35is connected diagonally between the side members 32 and 34 and a shortbeam member 36 extends between the side frame member 33 and the diagonalmember 35. Similarly, two other beam members 37 and 38 are connectedbetween the side member 31 and the diagonal member 35. Diagonallypositioned in each comer of the main frame are four members 39.

The platform 10 is rotatably supported on the intermediate frame 30 byroller members 40 which are carried on the intermediate frame at thelocations shown in FIG. 19. These roller members are arranged to engagethe transversely extending flange 24 on the platform 10. The platform isalso provided with a sleeve 44 which extends vertically downwardly fromthe center of plate 20 and receives a upwardly extending spindle 42connected to frame member 35. Consequently, as can be seen, the platform20 is freely rotatable relative to the intermediate frame 30.

The platform is enclosed by a rectangular housing defined by fourvertically extending plates 50-53 which are respectively connected tothe top surfaces of the frame members 3l-34. Additionally, similarplates 54 are positioned angularly in each corner between thesideplates, and a top cover 56 is joined to the upper edges of thesideplates 50-53 at an elevation corresponding to the elevation of thecircular plate 20.

Power means are provided for selectively rotating the support platforml0 relative to the intermediate frame 30. These means could take avariety of forms; however, as best shown in FIGS. l8, l9, and 21, thepreferred drive arrangement comprises a friction drive unit 60 whichincludes a main, relatively large diameter friction wheel 62 having itsouter surface 64 covered with rubber or similar material. Wheel 62 iskeyed to shaft 66 which is rotatably mounted in suitable bearings 68 and70. As shown in FIGS. 19, and 21, the bearings are supported by members72 and 74 which extend between the members 37 and 38 of the intermediateframe 30. The wheel is located so as to be in vertical alignment withthe lower surface of the platform flange 24.

Referring to FIG. 21 it is seen that the bearing 68 is carried by aU-shapcd member 76 which is seated over the support member 72 andcarried on spacer washer 77. The member 76 is merely seated on member 72so as to be capable of slight pivotal movement about member 72. It isprevented from moving longitudinally on member 72 by a pair ofvertically extending stop members 79 (See FIG. 19).

The bearing 70 is similarly mounted on a U-shaped support or mountingmember 78 which is carried from the support member 74 by Bellevillesprings 80. These springs function to maintain a desired preload betweenthe friction wheel and the flange and, additionally, when the platformdeflects slightly under load, the springs permit a slight deflection ofthe friction wheel 64. Consequently, the proper drive engagement ismaintained between the friction wheel 62 and the flange 24 at all times.

The drive or friction wheel 62 could be driven in many different ways;however, in the embodiment under consideration, a conventionalreversible electric motor 86 provided with a brake unit 88 is used. Asshown, the'motor and brake 86, 88, are supported from a platform carriedby the intermediate frame 30. The output shaft of the motor 86 isconnected with a right-angle gear unit 84 carried by intermediate framemembers 37 and 38. The right-angle drive unit 84 is drivingly connectedwith the wheel 62 by couplings 82 and shaft 83. As can be appreciated,this drive assembly permits the platform 10 to be rotated in eitherdirection about its vertical axis and stop at substantially any desiredlocation.

In order to permit the platform to be locked in desired positions ofrotation during roll changing, a lock unit 90 is provided. Referring toFIGS. 18 and 19, it is seen that the lock unit 90 includes a verticallyreciprocable lock pin 92 having a tapered upper end. The lock pin 92 iscarried in a sleeve or guide member 93 for reciprocation by a fluidcylinder 94. The guide sleeve 93 and the fluid cylinder 94 are bothconnected to and carried by a support plate 96 mounted to theintermediate frame member 36. Tapered pin receiving openings areprovided on the underside of platform 10 for locking engagement by theupper end of the pin 92. Referring to FIG. 18, it is seen that a pinreceiving member 98 is positively connected to the underside of theplatform. Any number of such receiving members can be provided atdesired locations under the platform. Consequently, after the platformhas been rotated to the desired location, actuation of the cylinder 94will cause engagement of the lock pin 92 to thus lock the platform 10against rotation.

For reasons which will hereafter become apparent, the entireintermediate frame 30 and the platform are supported from a main baseframe assembly indicated generally with the reference number 100.Referring to FIGS. 18 and 20, it is seen that the main base frame isformed primarily by four large beams 101 through 104 which arepositioned about an access or inspection pit 106.

As previously mentioned, according to the invention, the platform 10 isarranged to be raised and lowered so that both work-rolls and backuprolls can be changed. Although many different arrangements could beprovided, according to the subject embodiment, this is accomplished bysupporting the intermediate platform 30 from the main base frame 100 byfour scrcwjuck units 108. As noted in FIGS. 19 and 20, the screwjuckunits 108 are positioned so as to engage the under surfacesofintermediatc frame members 31 and 33 at location 109. The jacks 108are simultaneously driven by a reversible electric motor and brake unit110 which is connected with the scrcwjacks 108 by right-angle drives 113and 114 and drive shafts 116 interconnected by conventional couplings.Con sequently, the platform 10 can be moved to any desired verticalposition; and, because the rotating drive unit also moves with it, itcan be rotated at any vertical position.

To assure proper guiding of the intermediate frame 30 during itsvertical movement, four vertically extending guide posts 120 aresupported from the base frame 100 by pedestals 122 (See H6. As shown inFlG. 19, the guide posts 120 extend upwardly through guide sleeves 124carried by plates 126 positioned in the corners of the intermediateframe as shown in FIG. 19. As is apparent, this arrangement preventslateral shifting of the intermediate frame or platform during itsvertical movement.

Although not of importance to the present invention, support posts 128(See FIGS. 18 and 20) are provided to support the platform 10 when it isin its lower position as shown in FIG. 18. These support posts 128extend vertically upward from the access or pit 106 and are positionedto engage the under surface of the platform 10. Accordingly, thescrewjacks must carry only the weight of the intermediate frame when theplatform is in its lower position. This avoids possible damage to thesupport rollers 40 or the screwjacks 108 when the roll assemblies arebeing transferred to and from the platform by an overhead crane.

As can be appreciated, roll changing support platforms formed accordingto the invention can be readily utilized for changing both thework-rolls and the backup rolls in a fourhigh mill. Merely by providingthe platforms with sufficient vertical movement to allow them to shiftto the height corresponding to all of the rolls, the rolls can be simplymoved from the mill directly into the platform. However, because of thesubstantial height of some mill stands, a platform capable of moving toall the desired levels would require an extremely large elevatingmechanism. For this reason, according to a further aspect of theinvention, it is preferable to use the roll removing platform incombination with a specially designed mill stand which is provided withmeans to allow the rolls and rolls sets to be shifted to differenthorizontal elevations within the stand. For reasons which will hereafterbecome apparent, this combination provides substantial advantages.

Mill Stand B Broadly, the construction and operation of mill stand B canbest be understood by reference to FIGS. 1 through 4. in general, themill stand 13 includes a basically conventional frame 150 which includesa pair of side frames 152 and 154 having the usual access openings orwindows." The side frames 152, 156 are joined at their upper end by acrown member 156. Conventional screwdown screws and drive mechanisms 158and 160 are provided to provide the necessary rolling forces.

The embodiment shown is a four-high mill and includes a pair ofrelatively small diameter work-rolls 162a and 162b.

The work-rolls are each associated with a corresponding backup roll 164aand l64b. The work-rolls are driven in a conventional manner byreleasable spindles 166 which extend from a main gear housing 168 drivenby a prime mover not shown. Additionally, a conventional spindle supportassembly 169 is provided to maintain the spindles in position when thework-rolls are removed.

Referring to FIGS. 3 and 4, it is seen that the upper backup roll 164ais carried in chocks 170. Although only the left-hand chock (as viewedin FlG. 1) is shown, it is to be understood that the right-hand chock isof basically the same construction. lt will be noted that the chock 170is mounted for vertical sliding movement in the side frame window andretained therein in a conventional manner by keeper plates 172 whichengage vertically extending grooves formed in the chock. The keeperplates 172 are, of course, arranged so that they can be moved laterallyto permit the backup roll and its chucks to be moved transverselythrough the mill window. In the embodiment shown, the keeper plates 172are provided with elongated mounting openings which receive releasablestud bolts 173.

The lower backup roll l64b is similarly provided with chocks 174 whichare engaged by keeper plates 176. Keeper plates 176 are received invertical grooves formed in the lower backup roll chocks 174. A recess177 is formed centrally of each keeper plate for passage of wheelassemblies 252 when the lower backup roll is in the position shown inFIG. 5. Additionally, as best shown in H6. 5a, the plates are tapered atsurfaces 179 to guide the backup roll chock into its proper transverseposition when it is lowered from the position shown in FlG. 5 to theposition shown in FIG. 3.

The work-rolls 162a and l62b are provided with chocks 180 and 182 whichare related so that the work-rolls can be removed from the mill stand asa set or a unit. In particular, it is seen that the lower work-rollchocks 182 are engaged by transversely driven keeper plates 184 whichcan be selectively actuated by fluid cylinders 186. As best shown in H0.3, the upper work-roll chock is carried by the lower work-roll chockbetween a pair of upwardly extending legs 188 formed on the lowerwork-roll chock. Keeper plates 190 extend from legs 188 into engagementwith vertical grooves formed in upper work roll chock 180. Conventionalsets of counterbalance cylinders 191, 192, and 193 are built into thevarious roll chocks.

As can be appreciated, FIG. 3 shows the rolls in their normal workingposition. To permit the work-rolls to be removed from the mill stand itis, of course, necessary that the backup rolls be separated or removedfrom engagement with the work-rolls. In the subject embodiment, this isaccomplished by a novel roll lifting and elevating assembly. Referringspecifically to FlGS. 4, 11, and 12, it is seen that carried within themill frame crown 150 is a lift assembly 200 adapted to lift the upperbackup roll and its chocks away from the upper workroll. Although thelift assembly 200 could be a variety of different arrangements, in thepreferred embodiment it includes a large diameter hydraulic cylinder 202supported from a frame 204 carried in the crown 150. The hydrauliccylinder 202 is positioned with its piston rod 206 extending verticallyupwardly. The upper end of the piston rod 206 is connected by a pin 207to a pair of plate members 208 which are connected by transverselyextending plates 209. Pinned to the outer end of the plates 208 andextending downwardly therefrom are a pair of support or hanger rods 210.The lower ends of hanger rods 210 are each pinned to a pair of supportplates 212 which extend between members 214. As best shown in FIG. 12,the outer ends of the members 214 are each welded or otherwisepositively connected to chock hanger members 216. Referring to F103. 4and 11 it is seen that the chock hanger members 216 extend in parallelrelationship through the top of the mill between the windows of sideframes 152 and 154. Each of the hanger members 216 includes an inwardlyextending lip or flange portion 128. Support plates or bearing surfacemembers 219 are carried generally at the opposite ends of each of themembers 216.

Referring to FIG. 12 is is seen that the upper backup roll chockincludes outwardly extending flange or lip portions 220 which extendoutwardly over the bearing surfaces 219 carried on the flanges 218.Consequently, by controlling the actuation of the lift cylinder 202 theupper backup roll 164a can be lowered into position on the upperwork-roll as shown in FIG, 3. Alternately it can be lifted away from thework-rolls to the position shown in FIG. 4 so as to free the work-rolls.

As can be appreciated, in order to permit the work-rolls to be easilymoved out of the mill stand, not only must the upper backup roll belifted away from the work-rolls, but also, means must be provided topermit free movement of the work-rolls relative to the lower backuproll. For this reason, each ofthe lower work-roll chocks 182 areprovided with a pair of rollers 222 mounted for rotation about ahorizontally extending axis. A second pair of rollers 224 are alsocarried on the lower work-roll chock and positioned with their axis ofrotation extending vertically. The rollers 222 and 224 are arranged toengage elongated truck forming members 226 carried in the lower backuproll chocks I74. Referring to H65. 1 and 3, it is seen that the trackforming members 226 are carried in grooves or slots formed in the top ofeach of the lower backup roll chocks and extend transversely through themill. To lift the work-rolls away from the lower backup roll, thetrackforming members 226 are arranged to be actuated between a loweredposition shown in FIG. 3 and a raised position shown in FIG. 4. Thiscould be accomplished with different arrangements; however, the subjectutilizes hydraulic cylinders 228 carried in each of the backup rollchocks 174.

Referring more particularly to FIGS. 2 and 17, it is seen that the tracksections 226 are positioned so that their outer ends meet withcorresponding track members and wear plates 230 carried on the top ofthe platform 10. Platform is alsoprovided with parallel grooves or slots232 arranged to receive the guide rollers 224 which extend downwardlyfrom the lower surface of the lower work-roll chock 182. Accordingly,when the platform 10 has been moved to an elevation corresponding to theelevation of the track member 226 the work-rolls can be moved or rolleddirectly from the mill stand onto the platform. Thereafter, the platformcan be rotated 180 to bring the new or reconditioned work-roll set whichhas previously been positioned on the other pair oftrack members 230into alignment with the mill stand. This new work-roll set can then bemoved into the mill.

As previously discussed, it would be possible to arrange the platform 14so that it could have an amount of vertical adjustability sufficient toallow it to be moved to elevations that would permit it to receive thebackup rolls from their normal working positions. In accordance with afurther aspect of the subject invention however, the lower backup rollis arranged to be shifted a substantial distance vertically while it isin the mill stand. This allows a smaller amount of verticaladjustability of the roll receiving platform to satisfy the need forbackup roll removal. Moreover, the resulting combination is moreadvantageous for several other reasons.

Referring to FIGS. 4, l5 and 16 the structural details of the preferredembodiment of the backup roll elevating assembly 250 will be described.As shown, in FIGS. 4 and the lower backup roll chock is provided withsmall wheeled carriages 252 each of which include support rollers 254and guide rollers 256. The rollers are positioned to engage an elevatingtrack section or platform 258 mounted transversely in the base of themill stand. As shown, platform 258 has transversely extending tracks 260carried thereon. The elevation track section 258 is arranged to beactuated upwardly by a large diameter hydraulic cylinder 262 carried inthe base of the mill stand. As best shown in FIG. 15, the piston rod 264of the cylinder 262 is positioned to engage the center of the elevatingtrack section 258.

To assure that the track section 258 moves upwardly without lateralshifting or tilting, an equalizing unit is provided. This unit includesa pair of guide rods 266 which extend downwardly from the bottom oftrack section 258. The guide rods 266 pass through guide sleeves oropenings in the base of the mill stand. Additionally, the guide rods aremechanically inner connected so as to require that they both movesimultaneously. In particular, it will be noted that the lower endportion of each of the guide rods 266 has a track gear section 268formed thereon. A pair of pinion gears 270 engage the gear section 268of each of the guide rods 266. The pinion gears 270 are keyed orotherwise positively connected to a horizontally extending shaft 272which is rotatably carried by a bracket 274 extending downwardly fromthe base of the mill stand. Accordingly, when the hydraulic cylinder 262is actuated to move the elevating platform 258 upwardly, the guide rods266 are both constrained to move upwardly an equal amount, therebyassuring precise guided movement of the platform.

Although, it would of course be possible to support the platform 258 invarious selected elevational positions through the use of the hydrauliccylinder 262, it is preferable that there be a positive mechanicalsupport. For this reason, support units 290 are provided at each end ofthe track 260. The support units 290 are identical in construction andaccordingly, only one will be described in detail. Referring to FIGS. 13and 14, it is seen that each of the support units 290 includes a pair ofoscillatible arms 292 and 294 which are pivotally connected throughrespective pins 296 and 298 to a base frame member 300. Referring toFlG. 13 it will be noted that each of the arms 292 and 294 include twospaced support surfaces 301 and 301', 302 and 302'. When the arms are inthe solid line position shown in H0. 13 the tracks 260 are in theirlower most position. When the tracks are moved upwardly to the elevationindicated by small letter a, the arms can be oscillated to the dottedline position identified with the reference numerals 304 and 304. lnthis position the support surfaces 301 and 301'; are under the tracksections 260 as shown by dotted lines. Consequently, the track sectionsare given a positive mechanical support.

When the tracks 260 have been moved to the elevation indicated by smallletter b, the arms are actuated to the dotted line position identifiedby reference numerals 306 and 306'. In this position the supportsurfaces 302 and 302' are directly under the tracks and serve to providethe desired mechanical support.

The means for oscillating the arms could take a variety of forms;however, the preferred embodiment the means utilized preferablycomprised a fluid cylinder 310 which is pivotally supported from a frame312 which depends from the support frame 300. The piston rod 314 of thecylinder 310 extends into pivotal engagement with a pair of lever arms316 which are connected to the arms 392. Additionally, the arms 292 and294 are drivingly connected by mating gear segments 318 and 320 attachedto their inner or lower most ends. This arrangement, of course, assures,that movement of arm 302 under the influence of cylinder 310 produces acorresponding movement of arm 294.

Roll Inserting and Removing Apparatus C Although many different types ofdevices could be provided for moving the rolls into and out of the millstand, the preferred arrangement is as best shown in F165. 6-10.Referring particularly to FIG. 6 it will be seen that the roll removingand inserting apparatus C includes a pair of long stroke hydrauliccylinders 350 and 352. The cylinders 350 and 352 are positioned ingenerally parallel relationship and have their respective piston rods354 and 356 extending toward the mill stand. Mounted at the ends of thepiston rods are connectors or roll engaging elements 352 and 360.Referring to FIG. 8 it is noted that the two cylinders 350 and 352 areat slightly different elevations.

The manner in which the connecting members 358 and 360 engage thework-rolls can best be understood by reference to FIGS. 7 and 10. Notethat the connecting member 360 extends outwardly a distance greater thanthe connecting member 358. The member 360 terminates in a pusher unit362 arranged to engage a short outwardly extending portion 364 connectedto a chock of the lower work-roll. The connccting member 358 however, isrelatively shorter and has an overhanging anddownwardly extending lip364 carried on its outer end. A outwardly extending arm or connector 366is welded or otherwise positively connected to the chock of the lowerwork-roll. This arm has an upwardly extending lip 368 at its outer end.FIG. l8 shows the normal relationship between the connector 358 and thearm 366. When the workroll assembly is to be removed from the millhowever, it is moved upwardly a short distance by actuation of theelevating cylinder 262 and the track elevating cylinders 228 (See FIGS.4 and 15). The upward movement of the work-rolls causes the lip portion368 of arm 366 to move under the downwardly extending lip portion 364 ofthe connector 358. Additionally, the member 364 comes into alignmentwith pusher 362 (See FIG. 7). Thereafter, actuation of the cylinders 350and 352 will cause the work-roll set to be pushed out of the mill.Because of the relative length differences between the connectors 358and 360, the platform can be rotated without disconnecting or moving thecylinders 350 and 352. Additionally, the new work-roll assembly whichhas similar arm and pusher portions will rotate directly into engagementwith the connectors 358 and 360. During the period that the usedwork-roll is being rotated away from the connecting elements the pistonrods 354 and 356 would normally be relatively unsupported. For thisreason, a leg portion 370 depends from each connector is provided toengage the track and support the free end of the piston rod.

The connector elements 358 and 360 are also arranged to be selectivelyconnected to the lower backup roll chock. Referring to FIGS. 6, 9 and 10it is seen that pins 372 and 374 extend transversely through openingsformed in each of the connecting units 358 and 360. These pins arearranged so they can be manually moved into and out of the openings.Vertical lock pins 376 are manually insertable to lock the pins 372 and374 in position. In FIG. 8, the lower backup roll assembly is shown asbeing provided with arms 380 and 382 which terminate in end portionshaving pin-receiving grooves. As the lower backup roll is movedvertically, these grooves receive the transversely extending pins 372and 374. It is important to not in FIG. 6 that the arm portions engagethe connector 360 are double and which receive the outer most end of theconnector (which end is the pusher for the work-roll assembly). Afterthe backup rolls have been moved to the platform the pins 372 and 374are manually removed so that an overhead crane may take the backup rollset from the platform. The new backup roll set can thereafter be loweredinto position directly over the arms and the pins reinserted.

Typical Cycle of Roll Changing Operation As previously mentioned, thesubject apparatus can be utilized for changing only the work-rolls or,changing both the backup rolls and the work-rolls. The most often usedprocedure is, of course, changing the work-rolls. A preferred procedurefor changing work-rolls will be described; however, it should beunderstood that the described procedure is merely one way in which theequipment can be utilized to change work-rolls.

When it is desired to change work-rolls, the platform 10 is rotated tobring one of its sets of tracks into alignment with the mill stand. Theplatform locking pin 92 (Sec FIG. 18) is preferrably extended to lockthe platform in position. The counterbalance and contour cylindersbetween the work-rolls and the backup rolls are shut off. The screwdownscrews are actuated to their uppermost position and the upper backuproll is elevated by actuating the lift cylinder 202 (See FIG. 11).Thereafter, the tracks 226 in the lower work-roll chocks are actuatedupwardly and lift the work-roll set away from the lower backup roll.Subsequently, the elevating mechanism 250 is actuated to raise the lowerbackup roll a distance indicated by the reference letter a in FIG. 13.The lower backup 10 roll is then locked in this position by actuation ofthe support assembly 290.

Of course, during the movement of the lower backup roll to the elevationa, the connector arms 364 and 366 (See FIGS. 7 and 8) move intoengagement with the latching member 360 and 358. Thereafter, thecylinders 350 and 352 are actuated to push the used roll assembly out ofthe mill and on to the platform.

Normally, a new work-roll set will have been previously positioned onthe platform. Consequently, the platform is then rotated and the newwork-roll set brought into alignment with the mill stand. The rotationof the platform causes the engaging arms on the chocks of the newwork-roll set to enter the connectors on the inserting removingapparatus C. Thereafter the cylinders 350 and 352 are actuated to movethe new set to the mill. The above-described sequence of operationsregarding the lifting and separating of the rolls is then carried out inreverse order and the work-rolls brought to their final workingposition.

If it is desired to change the backup rolls, the same basic sequence ofoperations required for changing the work-roll set is carried out;however, after the used work-roll set has been moved to the platform,the platform is lowered and the cylinders 350 and 352 retracted. Theused work-roll set is thereafter taken away by an overhead crane leavingthe platform in front of mill window free and clear. Subsequently, theelevating assembly 250 shown in FIG. 15 is actuated to move the lowerbackup roll set to a position indicated by reference line b in FIG. 13.The support assembly 290 is then actuated to its upper most supportposition to support the lower backup roll.

With the lower backup roll assembly in the raised position the liftingmechanism 200 (Shown in FIG. 11) is operated to lower the upper backuproll into position on the lower backup roll (See FIG. 5).

Note that the upper backup roll chocks have small extended legs 380which engage the lower backup roll chock to assure alignment and supportthe upper backup roll spaced above the lower. The upward movement of thelower backup roll has, of course, brought the connectors 360 and 358into engagement with the connector pins 372 and 374 (See FIG. 6) thecylinders 350 and 352 are then actuated to push the backup roll set fromthe mill. Once the set is on the platform it is preferably immediatelytaken away by an overhead crane and a second backup roll set loweredinto position over the connecto. members. This set is then pulled backinto the mill and the upper backup roll lifted into position by theelevating assembly and the lower backup roll moved down to elevation atof FIG. 13.

Thereafter cylinders 350 and 352 are actuated back through the mill intoposition for receiving a work-roll set. Preferably, a new work-roll sethas been or was brought into position during the time of the backuprolls were changed. Platform 10 can then be rotated to swing this newset into engaged relationship to the inserting and removing apparatus.After being pulled into the mill the new workroll set is taken to itsworking position in the manner previously described. I

The subject invention has been described in great detail sufficient toenable one of ordinary skill in the rolling mill art to make and use thesame. Obviously, modifications and alterations of the preferredembodiment and its use will occur to others upon understanding of thisspecification and it is my intention to include all such modificationsand alterations as part of my invention in so far as they come withinthe scope of the appended claims.

lclaim:

1. Apparatus for changing the rolls in a mill stand comprising: ahorizontally positioned, generally circular platform provided with apair of generally parallel roll-receiving guideway forming meanspositioned substantially equal distances from the vertical centerline ofsaid platform for receiving rolls moved onto said platform from saidmill stand; a support frame means subjacent said platform and supportingsaid platform for free rotation about its vertical centeriine; powermeans for selectively moving said platform relative to said supportframe means between at least two vertically spaced e evations so thatsaid platform can be horizontally aligned wath at least one of saidrolls; lock means for selectively locking said platform in at least onepredetermined position of rotation; and, drive means movable verticallywith said platform for rotating said platform through a circumferentialextent of at least l80 at either of said two vertically spacedpositions.

2. The apparatus as defined in claim 1 including an intermediate framemeans positioned between said platform and said support frame, saidintermediate frame rotatably supporting said piatform and movablevertically therewith relative to said support frame; and, means forpreventing relative rotation between said support frame and saidintermediate frame.

3. The apparatus as defined in claim 2 wherein said drive means iscarried by said intermediate frame.

4. The apparatus as defined in claim 2 wherein said lock means isactuable to prevent rotation between said platform and said intermediateframe.

5. The apparatus as defined in claim 2 wherein said power means includejacks positioned between said support frame and said intermediate frame.

6. In the combination ofa mill stand including a plurality of generallyhorizontal rolls arranged in vertical alignment and a rotatably mountedplatform having a generally horizontal roll support surface positionedadjacent the mill stand with its axis of rotation extending verticallyand offset from the plane containing the axes of the rolls, theimprovement comprising: power means for selectively producing relativevertical movement between the support surface and the rolls whereby thesupport surface and at least two of the rolls can be brought in tohorizontal alignment; said power means including first means forselectively moving said support surface between at least two verticallyspaced elevations and second means for moving said rolls vertically insaid stand.

7. The improvement as defined in claim 6 wherein said mill stand is afour-high mill having a pair of work rolls with backup rolls associatedtherewith, and wherein said power means includes first means for lift ngthe upper backup roll independently of said lower backup roll.

8. The improvement of claim 6 wherein said power means further includesa second means for lifting the lower backup roll to at least twodifferent vertical positions.

9. The improvement as defined in claim 6 wherein said support surface ismounted for vertical movement between at least two positions androtating means are provided for rotating said surface at either of saidtwo positions.

.10. The improvement as defined in claim 9 including means for lockingsaid surface in selected positions of rotation.

11. The improvement as defined in claim 9 wherein said rotating meansmoves with said platform.

12. Apparatus for changing the rolls in a mill stand comprising: ahorizontally positioned, generally circular platform provided with apair of generally parallel roll receiving guideway forming meanspositioned substantially equal distances from its vertical centerline; asupport frame means subjacent said platform and supporting said.platform for free rotation about its vertical centerline; power meansfor selectively moving said platform relative to said support framemeans between at least two vertically spaced elevations; lock means forselectively locking said platform in at least one predetermined positionof rotation; and, drive means movable vertically with said platform forrotating said platform through a circumferential extent of at least l ateither of said two vertically spaced positions, said drive meansincluding a motor carried by an intermediate frame positioned betweensaid platform and said support frame means.

13, The apparatus as defined in claim 12 wherein said intermediate frameis supported from said support frame by a plurality ofjack means.

1. Apparatus for changing the rolls in a mill stand comprising: ahorizontally positioned, generally circular platform provided with apair of generally parallel roll-receiving guideway forming meanspositioned substantially equal distances from the vertical centerline ofsaid platform for receiving rolls moved onto said platform from saidmill stand; a support frame means subjacent said platform and supportingsaid platform for free rotation about its vertical centerline; powermeans for selectively moving said platform relative to said supportframe means between at least two vertically spaced elevations so thatsaid platform can be horizontally aligned with at least one of saidrolls; lock means for selectively locking said platform in at least onepredetermined position of rotation; and, drive means movable verticallywith said platform for rotating said platform through a circumferentialextent of at least 180* at either of said two vertically spacedpositions.
 2. The apparatus as defined in claim 1 including anintermediate frame means positioned between said platform and saidsupport frame, said intermediate frame rotatably supporting saidplatform and movable vertically therewith relative to said supportframe; and, means for preventing relative rotation between said supportframe and said intermediate frame.
 3. The apparatus as defined in claim2 wherein said drive means is carried by said intermediate frame.
 4. Theapparatus as defined in claim 2 wherein said lock means is actuable toprevent rotation between said platform and said intermediate frame. 5.The apparatus as defined in claim 2 wherein said power means includejacks positioned between said support frame and said intermediate frame.6. In the combination of a mill stand including a plurality of generallyhorizontal rolls arranged in vertical alignment and a rotatably mountedplatform having a generally horizontal roll support surface poSitionedadjacent the mill stand with its axis of rotation extending verticallyand offset from the plane containing the axes of the rolls, theimprovement comprising: power means for selectively producing relativevertical movement between the support surface and the rolls whereby thesupport surface and at least two of the rolls can be brought in tohorizontal alignment; said power means including first means forselectively moving said support surface between at least two verticallyspaced elevations and second means for moving said rolls vertically insaid stand.
 7. The improvement as defined in claim 6 wherein said millstand is a four-high mill having a pair of work rolls with backup rollsassociated therewith, and wherein said power means includes first meansfor lifting the upper backup roll independently of said lower backuproll.
 8. The improvement of claim 6 wherein said power means furtherincludes a second means for lifting the lower backup roll to at leasttwo different vertical positions.
 9. The improvement as defined in claim6 wherein said support surface is mounted for vertical movement betweenat least two positions and rotating means are provided for rotating saidsurface at either of said two positions.
 10. The improvement as definedin claim 9 including means for locking said surface in selectedpositions of rotation.
 11. The improvement as defined in claim 9 whereinsaid rotating means moves with said platform.
 12. Apparatus for changingthe rolls in a mill stand comprising: a horizontally positioned,generally circular platform provided with a pair of generally parallelroll receiving guideway forming means positioned substantially equaldistances from its vertical centerline; a support frame means subjacentsaid platform and supporting said platform for free rotation about itsvertical centerline; power means for selectively moving said platformrelative to said support frame means between at least two verticallyspaced elevations; lock means for selectively locking said platform inat least one predetermined position of rotation; and, drive meansmovable vertically with said platform for rotating said platform througha circumferential extent of at least 180* at either of said twovertically spaced positions, said drive means including a motor carriedby an intermediate frame positioned between said platform and saidsupport frame means. 13, The apparatus as defined in claim 12 whereinsaid intermediate frame is supported from said support frame by aplurality of jack means.